A patent license agreement is a contract and, naturally, the proper construction of a patent license agreement is generally a matter of state law. However, certain principles of federal law respecting patents create exceptions to the rules of construction that would normally obtain. Those exceptions create a trap for the unwary drafter.

The Supreme Court's recent findings regarding patentable subject matter may result in yet another set of guidelines for patent attorneys and examiners as to how best draft software and business method applications. Patent drafters often load up patents with seemingly extraneous language for a number of possible of reasons. Not least is the conventional wisdom that they have nothing to lose: it can't hurt and can only help. They may be mistaken.

In Medtronic, Inc. v. Boston Scientific Corp., the Court will decide which party bears the burden of proof in such a proceeding. In other words, must the patentee prove that the licensee's products are within the scope of the patent, or must the licensee prove the contrary?